NumberResearch Membership · Data 09/20/2026

Thousands-blocks in 650-521

This prefix’s ten 1,000-number blocks and who holds each — 10 on record · from the daily NANPA thousands-block report, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The ten 1,000-number thousand-blocks inside prefix 650-521 and who was initially assigned each. Under pooling these blocks often belong to different carriers — the single prefix-level “assignee” is usually just the pool / code holder, not who holds the numbers. ← all 650 blocks

Most active assignees, all time — NPA 650
NEW CINGULAR WIRELESS PCS, LLC 6
LEVEL 3 COMMUNICATIONS, LLC - CA 2
U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 1
COMCAST PHONE OF CALIFORNIA, LLC 1
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
2005-08-04 650-521-0XXX 0000–0999Assigned COMCAST PHONE OF CALIFORNIA, LLC 394L PALO ALTO CA
2006-05-05 650-521-1XXX 1000–1999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 PALO ALTO CA
2006-05-05 650-521-2XXX 2000–2999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 PALO ALTO CA
2006-05-05 650-521-3XXX 3000–3999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 PALO ALTO CA
2006-05-05 650-521-4XXX 4000–4999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 PALO ALTO CA
2008-02-01 650-521-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 PALO ALTO CA
2006-09-05 650-521-6XXX 6000–6999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 PALO ALTO CA
2006-09-05 650-521-7XXX 7000–7999Assigned NEW CINGULAR WIRELESS PCS, LLC 6010 PALO ALTO CA
2007-08-14 650-521-8XXX 8000–8999Assigned U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J PALO ALTO CA
2008-02-01 650-521-9XXX 9000–9999Assigned LEVEL 3 COMMUNICATIONS, LLC - CA 8826 PALO ALTO CA

Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.